In Utah, startup GreenFire Energy wants to replace the water used to convert geothermal energy to electricity in steam turbines or binary systems with CO2. What the company calls “CO2-G or CO2 Geothermal they claim will permanently sequester carbon. In their plan, CO2 – from natural sources or captured from man-made sources such as coal-fired plants – would be used cycled through deep injection wells, some of which would become a permanent part of the geology, the rest cycled continuously back through the plant and the earth.